Coriolis Force

A force which acts on a particle while it is moving along a path in a plane that is being rotated. For example, when wind blows along a path over the surface of the earth from the poles toward the equator, the rotation of the earth causes the wind to deflect to the right in the northern hemisphere and to the left in the southern hemisphere. It is the Coriolis force that causes the circular movement of the winds. It is also the Coriolis force that causes water to swirl in a spiral as it drains out the bottom of a bowl.